In a working vehicle such as, for example, a wheel loader, a front vehicle body portion and a rear vehicle body portion are flexibly linked together, and a construction machine that consists of a bucket or the like is provided to the front vehicle body portion. The operator digs up earth or sand or the like to fill the bucket, and loads it into a vehicle such as a dump truck or the like. While performing this type of work, sometimes the operator causes the steering to perform stationary steering operation. Stationary steering operation means that, in the state in which the working vehicle is stationary, the steering is greatly operated in either the left or the right direction.
When stationary steering operation of the steering is being performed, the life of the tires becomes short because the tires wear. Since the tires that are used on a wheel loader are comparatively high in price, the maintenance cost of the wheel loader increases if the tire life decreases.
In particular, in the case of a large sized wheel loader, the weight of the front vehicle body portion can easily become great, in order for it to be possible to charge a large amount of load into the bucket. Accordingly, if stationary steering operation of the steering is performed, sometimes it happens that the tires wear remarkably.
Although these are not technologies related to working vehicles such as wheel loaders or the like, it should be understood that a technique is known (Patent Document #1) of, during stationary steering operation of the steering, controlling the intake air amount and the fuel injection amount according to the load; and a technique is known (Patent Document #2) of, during steering stationary steering operation, operating a motor to support this stationary steering operation.